Spring suspension



` sept. 7,1937. Y M ,LLEY 2,092,614

SPRING SUSPENS ION Filed Feb. 8, 1936 y2 Sheets-Sheet l I8 I4 ,/6 l2, L

f f-XTZ j U 'l 2 if ff P"zi 37 r I3 li [JI-Ir Maa/fic@ 022g Sept.. 7, 1937. M. oLLl-:Y

` SPRING SUSPENSION 2 Sheets-Sheet 2 Filed Feb. 8, 1936 Summa/ud.

i vPerini-ed sept. v1,` 1937 n n 2,092,611

UNITED STATES PATENT oFF-ICE SPRING SUSPENSION Maurice Olley, Detroit, Mieli., assignor to General Motors Corporation, Detroit, Mich., a corporation o i Delaware Application February 8, 1936, Serial -No. 82,956 s claims. (Cl. 267-47) This invention relates to suspension systems characteristics of the suspension system and and particularly to vehicle suspension systems thereby retaining the coincidence of the lowest having resilientmeans ofwhich the effective spring rate at or about the normal position ofrate or stiil'ness (i. e., the change in loadrequired the parts irrespective of the actual normal load for each inch of deection or the suspended part being borne by the vehicle.

relatively to the unsuspended part ofthe ve- 'I'he above and other objects of the invention hicie) varies with the degree or deilection. will be apparent as' the description proceeds. s

It relates particularly to such variable rate According 4to the invention, the foregoing obsuspension systems in' which a low rate resilient jects are -achieved by varying the position in suspension is provided at or about the normal which the frame reactiony end of the spring is load position of the parts, while the effective rate c connectedto the vehicle frame. This is effected of the suspension system increases with increased by hydraulic means. actuated by the ordinary deflections of the parts away from their normal running oscillatory denectionsfof the wheels relaload position. tively to the vehicle frame', whenever these oscil- A variable rate P.suspension system of the fdreletiOnS take Place 'through a range Which dOeS 15 going type 1n whih a, higher rai-.e increasingly not extend equally on either side. of the position resists .deflection in either direction away from 0f the Wheel supporting` Ineens in thenerlnel. the normal position of the parts, is shown in co- Standing height Position 0f the Vehicle framepending United States patent application Serial ThedreWingS ShOW the epi-'01165111011 0f the ingo Number 37,311, wherein the resilient means conventien tc a meter vehicle independent Suspensists of a torsion rod spring of which the inherent Sion System of the general type `shown in cependrate is reduced in its position of normal deflecling United States Paientnpnlieetion Serial Ninntion, while its eiective rate is increased withinber 37,311-

creasing deflections in either direction away 'from In the drawings: Figure l is a plan view of the frame of a motor normal. y

, In such s suspension system it is desirable to vehicle to which lthe invention has been applied to both frontand rear wheels.

maintain the wheel supporting means relatively to the vehicle frame, in a normal position corre- Figure 2 is an enlarged elevational View of th sponding to the low rate position oi deilection of SuSPenSiOn unit hOllSing 0f the right hand Side the resilient means irrespective of any changes reni Wheel 0f Figure 1l eS Seen in the direction 30 in the normal loadcarried by the vehicle in 0f the arrows 2-2 of Figure 1. order toA obtain the advantages of the soft sus- Figure 3 is an enlarged sectional view `of the pension`at or about any normal load position tOrSiOn 1'0d Spring 0f enen Suspension unit and or 'the parts, with increasing stiirness. 1. e., a. Showinsihe manner in whichit is mounted withhigher spring orate) increasingly resisting deiiecin the Suspension unit h OliSinK- tions a'way therefrom. In other words, it is de- Figure 4 is a view in sectional elevation ofthe sirable to,k eep the variable rate resilient sus Operative elementawithin the housings shOWn in pension means with its low rate position of de# Figure 2 A ection in proper registry with a normal load Referring now tO'FlSnre 1,V the Vehicle frame l0 which varies. i includes a transverse member I rigidly attached w 'I'he object oi' the invention is to provide a varitherew- Mnnnted at each end 01' the transverse able rate suspension system with means commember i' for pivotal movement in a substantially pensating for changes in the normal load, in horizontal plane about pivot axes constituted 4by order* that the normal deilection of the resilient vkills pins 2 and I are brackets t and l ,constitutmeans shall be such that the relative changes in ing housings for each independent front wheel 45 spring rate for positions of denection at. and suspension unit. Y away from the normal load position shall remain The housings I and i extend from their king unchanged irrespective of the actual'normal load pins towards the transversemedian plane of the which may be borne. vehicle and-provide support for the substantially It is a further object oi the invention to provide horizontal pivot laxes of wheel supporting lever I0 automatic means to eil'ect the ilrst named object. i arms 8 and l, extending forwardly therefrom,

A more sp'ecinc 'object of the invention is a and carrying spindles l and l for road wheels Il y means o! varying the effective strength of the and Il respectively. spring in a variable rate vehicle suspension sys- Housings il and I3, (similar to the housings tem without interfering with the 'ehanging rate 4 and i. except that they attached to inter-engaging serrations .tubular pivot axis 29 is supported in needle bearraces 32 and 33 and 4tliefvehicle frame), are provided for each inde-- tively. A drag link 23 constitutesvthe connection between the branch 24ofthe steering arm 22 and a conventional steering gear (not shown).

The rear wheels I8 and I9 are driven from the diiierential gear 25 which is mountedon the vehicle frame, by means of drive shafts 26. and 21 universally jointed to the diierential gears and the stub. axles of the rear wheels I8 and I9, respectively and providedwith any suitable form of sliding or telescopic connection therewith (not shown).

As shown in Figure 1, the pivot and wheel spindle axes of each wheel supporting lever arm normally lie in vertical planes intersecting each otheron'the vehicle side oi the wheel.

The remaining elements of the suspension units being identical for each wheel III, Il, I8 and I9, it will be sufficient to describe those in conjunction with the housing I2.

Referring now particularly to Figures 2` and 3, the wheel supporting lever arm I4 is mounted in the housing I2 on a substantially horizontal tubular pivot axis 29 through the medium ofsuitable ings 3| in races 32 and 33, in the housing I2.

Fastened within the bore of the tubular pivot axis 29 through the medium of serrations 34, at

that end thereof carrying the wheel supporting lever arm I4, is a torsion rod 35 extending in` The inner end wardly of the vehicle therefrom. if this torsion rod 35 is provided with. serrations 36 lengaging the serrated bore oi' a torsion `tube 31, which encloses the remaining portion of the torsion rod extending inwardly of the vehicle from the tubular pivot axis 29 in the housing I2.- The other end of the 4torsion in the housing I2 in a pilot bearing constituted by an extension of the race 33. Suitable gland packings v38 and 39 are providedbetween the the tubular pivot axis 2 9 and the torsion tube 31 respectively.

The torsion tube is provided with a flange 49 to which is attached one end of a. lever 4I by rivets such as 42 or the like. The other end ci the lever 4I is pivoted to a rod 43 which has at its' oppo-v site end (as shown in Figure 4), a ball end 44 on the housing I2.

Means later to be described areproviniied4 to control the position oi the ram' 45 in its cylinder v46 and hence the position of the lever 4I.

755 ing I2. a lever arm 41 which is-attachedto the It will be 'seen that the torsien rod as in series with its enclosing torsion tube 31, torsionally resists pivotal movement of the wheel supporting lever arm about its pivot axis provided by the tubular member 29, and thus constitutes a means 'resiliently resisting upward. and downward deilections of the wheel I8 relatively to the vehicle frame, the spring reaction being taken throughV the'lever ai'ni4i and the movable ram 45 to the vehicle frame. f

As shown in Figure 4, there is, within 'the lio'us.`

bearing against a ram 45 in a cylinder mountedn tubular member 29 through the medium oi interengaging serrations 4B between the parts.

The lever arm 41 constitutes one link of a .toggle of which the other link is an auxiliary spring means 49, assisting, through the tubular member 29, torsional deflection of the end 34 of the combined torsion spring 35, 31 relatively tothe end 40 which is held bythe lever 4 I in either direction away Iromits'normal load position. As a result oi the .toggle connection; the auxiliary spring 49 assists torsional deflection of the' torsion spring to a lessening' extent with increasingdeflections-thereof in either direction away from its normal position and thereby provides a variable rate suspension system of the type` set forth.v

The lever arm 41 is provided with a pair o f lugs 50 and 5I constituting cams coacting with pistons 52 and 53 of a hydraulic damper to damp the' movement of the le'ver`41 and hence the wheel supporting means, in the manner describedincopending application Serial Number 37,311. compensating means are provided. in order that the toggle constituted by the lever 41 and the spring 49 will be straight inthe normal load position and hence in a position corresponding to the 'lowest spring rate oi' the variable rate combination, irrespective uf a change in the normal load actually borne by the vehicle. These com# pensating'means are made eiective by oscillations or Athe lever 41 whenever these oscillations` take place other than equally on either side of the normal straight position ofthe toggle. Such oscillations are madeeiective to move the lever arm 4I to a position in which, the torsion spring is wound up or unwound until the toggle is normally straight and in the position of lowest spring rate, with. the actual normal `load then being borne.

Referring now particularly to Figure 4, and it being.,l understood that the housing I2 forms a reservoir of oil, hydraulic means as follows are provided, automatically varying the position oi' the ram 4,5 andhence of the lever arm 4I and the frame reaction end 4I! of the torsion spring 35, 31 in accordance with variations in' thev ormal load borne by the vehicle. tube 1S carried In the top of the housing I2 a pump is provided ,consisting of a chamber 54 for 'a plunger 55 extending downwardly into the path of movement of thelever a'rm 41: 'The-plunger 55 is provided with a shoulder limiting the outward movement thereof under the iniiuence of a spring 56.l A

.spring loaded non-return ball check valve 51 is provided for the inux of oil' into the chamber 54 from a suctionv pipe 58 extending towards the bottom oi' the housing I2.- A spring loaded nonreturn ball check valve 5'9 is provided for thel delivery of oil from the pump into 'a pipe linei connected to the top ofthe cylinder49 of the ram 45. -A spring 6I between the ram 45 and the top of the cylinder'45 yieldingly urges the ram 1 45 into contact with the ball end of the rod 43.'

When the 'wheel I9 is carrying its lightest normal load the ram '45 is at the top o f the cylinder andw the lever 4I is in its highest position, while the car has a Istanding height such that the toggle 41-49 is straight corresponding lto3 the lowest spring rate position 'of the variable rate combination'.

With'a greater normalload there-will be a When thevel'iicle begins tomove.. however, the

passes over .uneven'surfac'es are .such that the 7 greater deection of the torsion spring and the standing'. height oi the vehicle Awill be reduced.

AV'ni -the' road, when the vehicle is overloaded.

lever arm 41 will frequently strike the plunger 55. Reciprocation of the plunger 55 pumps oil through the pipe line 50 and into the cylinder 46 depressing the ram 45 which through lever 4I winds up the torsion spring 35, 31 and thereby increases.

the standing height" of the vehicle until frequent contacto! the lever 41 andplunger 55 no longer occurs.

'I'he torsion spring 35,"31 having been wound 1o up to a mean position oi deiiection in which the toggle is straight, it will be appreciated that any further oscillations of the lever 41 sumcient to actuate the plunger 55 would overdepress the ram 45, thus overcompensating for the increased load. l5 To prevent this occurrence, means as follows, are provided to remove oil from the cylinder 46 as fast as it is pumped in bythe plunger 55 when suilicient compensation has been secured.

In the lower part oi the .housing l! a pump is 20 provided consisting of a chamber E! for a plunger 5.3, extending ulwardly into the path of movement o f the lever arm 41. The plunger 63 is provided with a shoulder limiting the outward movement thereof under the inuenoepi a spring 54. A spring loaded non-return ball check valve 65 is provided for the inilux of oil into the chamber 5I from the cylinder 46 through a pipe line '66.-

The inlet valve 65 has a light spring easily overpowered by the :pressure in the pipe line 55. A

spring loaded non-return ball check valve 51 is` The shoulders on the plungers 55 and 63 have a ground seating in the chambers 54 and 52 respectively, so that when the vehicle is at rest there is no leakage past the pl-ungers.

It will be seen therefore that a variable rate running oscillations of the wheels relatively to the vehicle frame, when the vehicle is in motion, will rapidly adjust itselfv to changes in the normal load carried, has been provided. y

The suspension will always ride at or near .the position corresponding to the lowest spring rate of the variable rate spring suspension combiv nation. The closeness and rapidity oi' adjustment vwilldepend on ti'e separating distance between theends of the plungers 55 and G3 and the lever 41.

The combination is oi advantage for the suspension oi'- rear wheels, firstly because the nonparallel pivot and wheel spindlel axes of the wheel supporting lever arm provide for a conical swinging motion of the wheels which is calculated to increase the roll-stability and improve the steering -ability of the vehicle, while-because the.r

standing height of the vehicle body Vfrom the road is maintained constant irrespective of variations 'in` the normal load carried-extreme changes in the camber of the wheels which adversely affect lthe wear oi.' thetires and the 'steering andhanv suspension system which through the ordinary I claim:

1. Ina vehicle having a variable rate suspension system oi the torsion rod type, having one end of a torsion spring connected to a roadwheei supporting means and the other end thereof connected to the vehicle frame, means compensatingfor changes in the normal load borne by the vehicle by a turning adjustment of one end of the torsion spring about-itsaxis in .relation to the member to which the said'end is connected, whereby the same relative changes in spring rate for positions of deflection of the torsion spring at and away from their normal position, will ,be maintained irrespective of the normal load which may be borne.

2. 'I'he combination according. to claim 1 in which the variable rate isobtained by reducing the inherent rate of the torsion spring in its position of normal deiiection while its effective rate is increased with increasing deflections in either direction away from normal, said variations in effective spring rate being effected by,

means including an auxiliary spring acting on a lever armrigidly connected. to a .part of the torsion spring which is torsionally deflected by the load, and in which the turning adjustment of one end or the torsion spring is effected by means responsive to oscillations of the lever arm.

3. In a vehicle suspension system of thetorsion rod type, having a torsionv spring connected between a road wheel supporting means and the vehicle frame, a lever arm rigidly attached to aI partv of the torsion spring which is torsionally deectedby the load on the vehicle, said lever arm oscillating with changing deilections oi the torsion spring and the running oscilmeans relatively to th'e vehicle frame but having a mean position for a given load on the vehicle,

automatic adjusting means operative to change the relativerposition of the connection between thetorsion spring and one of the parts between whichdt is mounted, and thereby to restore the lever arm to the same mean position when the load on the vehicle is Vchanged and to Amaintain this mean position constant, said automatic adjusting means being responsive to the said running oscillations whenever these take place through a range which does not extend equally on either side `of the desired constant mean position.

4. The combination according to claim A3 `in which the .lever arm`.is attached to that part of `thetorsion spring which is connected to the road wheel' supporting means, and the automatic adjusting means' is operative between that part of the torsion spring which is connected to the vehicle frame, whereby the road wheel supportingV rneans is restored to the same mean position when the loadl on the vehicle is changed.

5. The combination according to claim 3 in lations of,` the road wheel and its supporting which the automaticadjusting means includes a y cylinder, a ram within. the cylinder, a pump plunger actuated by oscillations of the lever arm in one direction to pump fluid intothe ram cylinder, a second pump plunger actuated by oscillations oi' the lever arm in an opposite direction pumpedby the rst plungerI being unequal to the Avolume pumped by the second plunger when the running oscillations take place through a range b the desired constant mean position or the lever arm.

6. means -operatively connected .between a -road Wheel supportingv means and the vehicleA I rame, said vvehicle having, for an assumed normal lead,

'- a `certain standing height and normal position Aof the suspended parts of the vehicle relatively to the wheel'supporting means and to the road, adjustable mea'ns, to compensate for. changes in the normal load and to restore' andzmaintain the .said standing height-irrespective of the changes in the normal loa'd; said adjustable means Vbeing rinterposed between .theresilient means and one of the parts to which it is operatively connected at the point of connection between the resilient means and the said part, the adiustment'being automatically eected by means responsive to the running oscillation of the road wheel and its supporting -means relatively to the vehicle frame, whenever the said oscillationstake place through a range which extends unequally on either side o! lthat position'o'f the wheel-supporting means corresponding to the said standing height for the. assumed normal load.

F7, In-.a' vehicle' having resilient suspension means of thetorsion rod type, operatively connected between a road wheel supporting means.

and the vehicle frame, said vehicle having. foran assumed nornlaldoacl,A a certain standing height and normalpcsition of the suspended 4parts of the vehicle-relatively tofthe wheel supporting .means and to .the road, adjustable means 4to com# pensate lor changes in` th normal 4load and to restore and maintain the said standing height irrespective of the changes inl thenormal load, l said adjustable means being interposed. between the torsion spring andthe vehicle frame.4

8. In 'a vehicle 'having resilient suspension means. operatively connected between a road wheel supporting means and the vehicle frame, `saidyehicle having, ior .an assumed normal load.

1 a certain standing height and normal position of 45 the suspended parts of the vehicle relatively to the wheel supporting means and tothe road, acl- In avehicle having Vresilient suspension 1.aubaine which does' -not extend equally on eitherside of A' instable means to compensate. for changes in the normal load and to restore and maintain the said standing height irrespective oi'the changes in the normal load, said adjustable means being interposed between the resilient means and one of the partsto which it'is operatively connected- 4at' thel point of connection between the resilient means and -the said part, said adjustment being automatically effected by power mean's generated by. and responsive to, the running oscillations of the road'wheel and its supporting meansrelatively to the vehicle frame, whenever the said oscillaunequallyon either side of that position of the wheel supporting means corresponding tothe said standing height for the assumed normal load.

9.. In. a vehicle 'having resilient suspension tions take place through a range which extends means operatively connected between a road wheel supporting-means andthe vehicle frame, said vehicle-havin`g, for an assumed normal load,

a certain standing height and normal position of the suspended parts of the vehicle relatively to the wheel supporting means and to the road,

adjustable-means to compensate for changes in' sition of the ram within the cylinder being con trolled hydraulically by a pair of pumps actuated by means responsive to the running oscillations of the road wheel and its supporting means relatively to the vehicle. frame, and arranged to pump-oil into and out of the cylinder respective-'- ly,- in amounts varying to the extent that the oscillations take place through a range which ex tends unequallyon either sidel of that position of the wheel supporting means corresponding tothe said standing heightfor the assumed normal load. l I f MAURICE OLLEY.

'of thef-l above patent iring correctionas' follows Page"4 il.; ffr'atf' cciimn, elf-crine wqrariegd'ff.relacionar-.ana'.'that'v'thgiaaidf Letter-s resent should be read -wi'enjtnis-'- cen-semen chemischen-.i15- mm the desired constant mean position or the lever arm.

Wheel supportingv means and the vehicleA I rame, saidvehicle having, for an assumed normal lead,

'- a `certain standing height and normal position Aof the suspended parts of the vehicle relatively to the whee'l'supporting means ,and to the road, adjustable means, to compensate for. changes in the normal load and to restore' andzmaintain the .said standing height-irrespective of the' changes in the normal loa'd; said adjustable means Vbeing rinterposed between .theresilient means and one of the parts to which it is operatively connected at the point of connection between the resilient means and the said part, the adiustment'being automatically eected by means responsive to the running oscillation of the road wheel and its supporting means relatively to the vehicle frame, whenever the said oscillationstake place through a range which extends unequally on either side o! lthat position'o'f the wheel-supporting means corresponding to the said standing height for the. assumed normal load.

F7, In-.a' vehicle' having -resilient suspension means of thetorsion rod type, operatively connected. between a road wheel supporting means.

and; the vehicle frame, said vehicle having. foran assumed norxrlalioad,A a certain standing height and normalpcsition of the suspended 4parts of the vehicle-relatively tofthe whe'el supporting .means and to .the road, adjustable means 4to com# pensate for changes in` th normal 4load and to restore and maintain the said standing height irrespective of the changes inl thenormal load, l said adjustable means being interposed. between the torsion spring andthe vehicle frame.4

8. In 'a vehicle 'having resilient suspension means. operatively connected between a road wheel supporting means andthe vehicle frame, `saidyehicle having, ior .an assumed normal load.

1 a certain standing height and normal position of 45 the suspended parts of the vehicle relatively to the wheel supporting means and tothe road, ad

In avehicle having Vresilient suspension means -operatively connected .between a -roady ao'eaeia which does' -not extend equally on eitherside of A' instable means to compensate. for changes in the normal load and to restore and maintain the said standing height irrespective oi'the changes in the normal load, said adjustable means being interposed between the resilient means and one of the partsto which it'is operatively connected- 4at' thel point of connection between the resilient means and the said part, said adjustment being automatically effected by power mean's generated by. and responsive to, the running oscillations of the road'wheel and its supporting meansrelatively to the vehicle frame, whenever the said oscillations take place through a range which extends unequallyon either side of that position of the wheel supporting means corresponding tothe said standing height for the assumed normal load.

9.. In. a vehicle 'having resilient suspension means operatively connected between a road wheel supporting-means andthe vehicle frame, said vehicle-havin`g, for an assumed normal load,

a certain standing height and normal position of the suspended parts of the vehicle relatively to the wheel supporting means and to the road,

adjustable-means to compensate for changes in' sition of the ram within the cylinder being con trolled hydraulically by a pair of pumps actuated by means responsive to the running oscillations of the road wheel and its supporting means relatively to the vehicle. frame, and arranged to pump-oil into and out of the cylinder respective-'- ly,- in amounts varying to the extent that the oscillations take place through a range which ex tends unequallyon either sidel of that position of the wheel supporting means corresponding tothe said standing heightfor the assumed normal load. l I f MAURICE OLLEY.

'of thel above patent iring correctionas' follows Page"4 il.; ffxfatf' column, 6; rQrtne wqrariegd'ff.mediaset-.ana'.'that'v'thgiaeidf Letter-s fiasteile should be read wishing-' con-sesion eneriehse nie.- mm

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